1. Field of the Invention
The invention generally relates to a solar cell module for terrestrial use and more particularly to a concentrator for a solar cell module adapted to employ repeated internal reflection for effectively concentrating solar energy onto the active surfaces of solar cells of the module.
2. Description of the Prior Art
Photovoltaic devices have long been employed for converting solar energy to electrical energy. To enhance the efficiency of such devices various schemes, techniques and devices have been proposed and employed for directing solar radiation to strike the active surfaces of semi-conductive devices, often referred to as solar cells. For example, U.S. Pat. No. 3,973,994 discloses a photovoltaic device having thin layers of active material backed by a transparent substrate. The side of the substrate opposite the active layer is formed in a sawtooth configuration and is reflectively coated so that unabsorbed radiation is reflected back to the active layer at an angle resulting in total internal reflection. Consequently, incident radiation is caused to pass through the solar cell for a finite number of times until it is absorbed by the active layer. The teachings of this patent are incorporated herein by reference thereto.
U.S. Pat. No. 2,888,007 discloses a screen having slots through which light is focused onto a photo-electric element. The surface of the screen disposed toward the element is covered by a reflective surface between the slots and repeatedly reflects solar radiation until substantially all of it has been absorbed by the element.
U.S. Pat. No. 2,001,672 discloses a light sensitive cell in which light passing through and not absorbed by an active layer thereof is reflected back to the layer by a reflecting surface.
U.S. Pat. Nos. 3,179,861 and 4,055,761 were discovered in the course of a search, however, the teachings thereof are not deemed to be more pertinent than the disclosures of the patents aforediscussed.
As can be appreciated by those familiar with the design and operation of solar cell modules, devices having a capability of concentrating solar flux on the active surface of a planar solar cell tend to be bulky, complex, and in many instances impractical when employed in an operational environment.
It is therefore the general purpose of the instant invention to provide in combination with a solar cell an improved concentrator having a capability of achieving significant concentration of incident solar flux for significantly enhancing short-circuit current for the cell, without resorting to a use of ancillary concentration devices which tend to increase module depth.